“For mtDNA variation, some studies have measured Native American, European and African contributions to Mexican and Mexican American populations, revealing 85 to 90% of mtDNA lineages are of Native American origin, with the remainder having European (5-7%) or African ancestry (3-5%). Thus the observed frequency of Native American mtDNA in Mexican/Mexican Americans is higher than was expected on the basis of autosomal estimates of Native American admixture for these populations i.e. ~ 30-46%. The difference is indicative of directional mating involving preferentially immigrant men and Native American women. This type of genetic asymmetry has been observed in other populations, including Brazilian individuals of African ancestry, as the analysis of sex specific and autosomal markers has revealed evidence for substantial European admixture that was mediated mostly through men. In our 384 completely sequenced Mexican American mitochondrial genomes, 12 (3.1%) are of African ancestry belonging to haplogroups L0a1a’3’, L2a1, L3b, L3d and U6a7; 52 (13.6%) belong to European haplogroups HV, JT, U1, U4, U5; and K and the majority (320, 83.3%) are of Native American ancestry.”

what about the spaniards that ruled mexico years ago. wouldn’t they show up as “European” dna today?
The “immigrant ” preffering native American woman is farely common as with all races, but I see more immigrents marrying anglo women more than any other race. And im not surprised that they are native American domanent because of there Aztec bloodlines.